Add some girders

src/Dodge/Room/Foreground.hs

@@ -1,6 +1,7 @@
 module Dodge.Room.Foreground
     where
 import Dodge.Picture
+import Dodge.Base
 import Picture
 import Geometry
 import Geometry.Data
@@ -52,5 +53,56 @@ highPipe x y = pictures
     ,verticalPipe 5 orange (0.5 *.* (x +.+ y)) (-0.1) (-0.2) 
     ]
 
+girderZ :: Float -> Point2 -> Point2 -> Picture
+girderZ w x y = setDepth (-0.1) $ color red $ pictures $
+    [ thickLine [xt,yt] 3 
+    , thickLine [xb,yb] 3
+    ]
+    ++ map (flip thickLine 3 . flat2) ls
+  where
+    n = w *.* (normalizeV $ vNormal $ y -.- x)
+    xb = x +.+ n
+    yb = y +.+ n
+    xt = x -.- n
+    yt = y -.- n
+    ps = divideLineExact (w*2) xb yb
+    dia = rotateV (pi/4) n
+    ps' = map (\p -> intersectSegLine' xt yt p (p +.+ dia)) ps
+    ls = catMaybes $ zipWith (fmap . (,)) ps ps'
+girderV :: Float -> Point2 -> Point2 -> Picture
+girderV w x y = setDepth (-0.1) $ color red $ pictures $
+    [ thickLine [xt,yt] 3 
+    , thickLine [xb,yb] 3
+    ]
+    ++ map (flip thickLine 3 . flat2) as'
+    ++ map (flip thickLine 3 . flat2) bs'
+  where
+    n = w *.* (normalizeV $ vNormal $ y -.- x)
+    xb = x +.+ n
+    yb = y +.+ n
+    xt = x -.- n
+    yt = y -.- n
+    ps = divideLineExact (w*2) xb yb
+    (as,bs) = evenOddSplit ps
+    f a = map (\p -> intersectSegLine' xt yt p (p +.+ (rotateV a n)))
+    as' = catMaybes $ zipWith (fmap . (,)) as $ f (pi/4) as
+    bs' = catMaybes $ zipWith (fmap . (,)) as $ f (3*pi/4) as
+girder :: Float -> Point2 -> Point2 -> Picture
+girder w x y = setDepth (-0.1) $ color red $ pictures $
+    [ thickLine [xt,yt] 3 
+    , thickLine [xb,yb] 3
+    ]
+    ++ map (flip thickLine 3 . flat2) ls
+  where
+    n = w *.* (normalizeV $ vNormal $ y -.- x)
+    xb = x +.+ n
+    yb = y +.+ n
+    xt = x -.- n
+    yt = y -.- n
+    ps = divideLineExact (w*2) xb yb
+    ps' = map (\p -> intersectSegLine' xt yt p (p +.+ n)) ps
+    ls = catMaybes $ zipWith (fmap . (,)) ps ps'
+
+
 --highGirder :: Point2 -> Point2 -> Picture
 --highGirder x y =